Effects of cellulose nanofibrils on the cure kinetics of the phenol formaldehyde resin

Abstract

Phenol formaldehyde (PF) resin were treated with cellulose nanofibrils (CNF), and its effects on the cure kinetics of PF resin were evaluated. The curing of PF resin was a polycondensation exothermic reaction forming insoluble polymer. The Differential scanning calorimetry (DSC) analysis showed 3% CNF addition had prolonged the curing process of PF resin, and the Kissinger equation and Crane equation were introduced to show that the curing activate energy and reaction order of 3%-CNF-added-PF resin sample were obviously lower than control ones. The scanning probe microscopy (SPM) results exhibited that CNF particles were well-dispersed in the PF matrix. The non-isothermal kinetic study indicated that CNF had played a major role during late stage of non-isothermal polymerization, increasing the crosslinking points in the PF resin and reducing the energy needed for PF resin curing. Thus, the addition of CNF had a positive effect on the curing of PF and made the curing more perfect.